Common anti-theft steering shaft locks include a shiftable bolt on one of the steering shaft and the steering column and a keeper on the other which receives the bolt to inhibit rotation of the steering shaft. In some common locks, friction between the bolt and the keeper resulting from residual torque on the steering shaft may inhibit unlocking withdrawal of the bolt from the keeper. Such residual torque may, for example, result from parking the vehicle with a front tire pressing against a curb. An anti-theft steering shaft lock according to this invention incorporates a lost motion connection between the steering shaft and the one of the keeper and bolt thereon to relieve residual torque on the steering shaft after the bolt engages the keeper and thereby facilitate subsequent unlocking withdrawal of the bolt from the keeper.